The European Union plans to widen the number of radio frequencies that can be used for 3G mobile networks, but an EU official said on Wednesday the most attractive bands for rural areas are not yet available.

Mobile operators are looking for new space for the faster 3G networks as current frequencies are in full use in many countries.

They prefer lower bands like the 900 MHz because signals carry longer distances at this frequency and can also penetrate buildings. This means carriers have to build fewer radio base stations to cover sparsely populated areas while also improving service for high value users in business centers.

The European Union, however, is looking first at the higher 2.5 GHz band, a senior European Commission official said.

"We are discussing with member states introducing more flexibility in 3G -- expanding to 2.5 (GHz) band and maybe also 900 (MHz) could be an option," Fabio Colasanti told Reuters in an interview at IST 2006 fair.

In some countries, like Finland, operators can already use the 900 MHz frequency for 3G, but Colasanti said any EU wide initiative on the frequency would take time as the Commission fears wider moves could distort competition in some countries where 2G operators use that bandwidth.